C'mon, you can't just throw out a number like that and not provide an exhaustive list of all 15 targeted diseases!
The article (and its linked source) mentions Chikungunya, Crimean-Congo hemorrhagic fever, Dengue, Ebola, Malaria, Marburg, Lassa fever, MERS, and COVID-19. Reading through the articles in depth also reveals mentions of Nipah, HIV, and Tuberculosis. That's 12. So what are the other 3?